Aluminum compounds such as alum, sodium aluminate, etc., have been used for years as coagulant aids to help clarify influent water. These aluminum containing materials neutralize the charge on turbidity particles in the water and hydrolyze to form insoluble precipitates that, in turn, entrap additional particles. In most cases, these large particles (flocs) settle with the aid of clarifier or like devices and are collected as sludge exiting from the clarifier sludge draw off line. Ideally, clarified effluent water flows over the top of the clarifier into a collection weir and is then ready for further water treatment processes such as filtration, softening and ion exchange, or the effluent can be used directly, without further processing, as makeup water to an operating system such as a cooling or boiler system.
Occasionally, clarifier system upsets cause the aluminum containing flocs or particles to "carryover" or flow into the effluent collection weir. In these instances, troublesome aluminum induced deposits can form in cooling systems or boiler systems which are supplied with such aluminum containing makeup water.
Carryover aluminum is usually in the trivalent state and may, depending on water chemistry, exist in the form of aluminum hydroxide, aluminum silicate, aluminum phosphate, aluminum sulfate, etc. The problem may be encountered at as low as 0.5 ppm Al.sup.+3 in the system water. Moreover, when anionic deposit control agents, such as polyacrylates, are used in the cooling or boiler system, the available carryover Al.sup.+3 or its hydrated Al(OH).sub.3 form or any resulting Al.sup.+3 containing compound can interfere with the deposit control agent, thus rendering the latter incapable of performing its intended deposit control function.
Accordingly, there is a need in the art to provide a treatment that may be effectively used to minimize water system fouling in systems experiencing the aforementioned problem of aluminum carryover.
These and other problems are alleviated by addition to the requisite aluminum containing system water of a specific water soluble acrylic acid/allylhydroxypropyl sulfonate ether copolymer (hereinafter AA/AHPSE).